Process for the manufacture of sulphonic acids or their salts



Patented Dec. 5, 1933 PROCESS FOR THE MANUFACTURE OF SUL- PHONIC ACIDS R THEIR SALTS Hyman signor to The Lhnburg, Amsterdam,

Flintkote Corporation, Boston,

Netherlands, as-

Mass., a corporation of Massachusetts No Drawing.

Application October 16,1930, Serial No. 489,241, and in the Netherlands October 19,

Claims.

In the production of sulphonic acids by subjecting orgamc compounds to the action of sulsulphonated products are found to be more or 5 less contaminated with sulphuric acid and sulphurous acid, whilst also the so-called lignine sulphonic acids from sulphite-lye are contaminated with electrolytes.

For various uses the presence of inorganic acids or salts in sulphonic acids is objectionable.

It appears, for instance, in the use of sulphonic acids as emulsifier for so-called soluble oil that the inorganic salts, such as sodium sulphate, often crystallize out after some length of time, thus causing obstructions in the pump lines'and other connections. Further it appears that when sulphonic acids are used as emulsifier for asphalt and the like substances the salts contained in the acids have a flocculating action on the emulsion and consequently render the emulsifier unsuitable.

Now according to the present invention sulphonic acids or their salts are obtained in a sufilciently pure state for technical purposes from an aqueous liquid in which they occur together with electrolytes. The invention is based on the fact that organic bases, such as e.g. aniline, do not combine with these electrolytes or only form such compounds'as are soluble in water, whereas with the sulphonic acids to be purified they form compounds that are insoluble in water. Thus the process according to the invention consists in treating the aqueous liquid containing the sulphonic acids to be purified with any suitable organic base, for instance aniline, whereupon the compounds of the organic base and the sulphonic acids thereby precipitated are separated from the rest of the aqueous liquid, after which the said acids or their salts may be liberated from these compounds. The invention will now be described more specifically in connection with its application to the production of sulphonic acids in a pure state from the acid sludge formed in the treatment of a mineral oil with sulphuric acid, though it is by no 45 means restricted to this mode of application. In

this case the raw material used in the performance of the process according to the invention may be the acid sludge itself, e.g. such as produced in the acid treatment of the SO2-extract from mineral oil, in particular spindle oil, or such as produced in the first acid treatment or treatments of the SOz-rafilnate from this oil. If on the other hand, acid sludge is used which is formed in the later treatments with sulphuric acid in view of 55 the more intensive refining of mineral oil, then aniline sulphate which is soluble in a large part of the sulphuric acid can already be removed by a preliminary treatment. This pretreatment consists in adding a not too large quantity of water, whereby two layers are formed. One layer contains the greater part of the sulphonic acids originally present in the acid sludge mixed with some sulphuric acid and water, whilst the other layer consists of diluted sulphuric acid in which some sulphonic acid remains dissolved. Thus by separating of the sulphuric acid originally contained in the acid sludge is removed, and in this case the separated sulphonic acids form the raw material for the process according to the invention. The raw material, i. e. the acid sludge or crude sulphonic acid, is first dissolved in water, whereupon aniline or any other suitable organic base is added to the aqueous solution. The sulphuric acid in the solution is thereby converted into water, and the sulphonic acids into aniline sulphonates which, being insoluble, settle out of the aqueous liquid. The consistency of the precipitated aniline sulphonate is proportionate to that of the sulphonic acids and varies at ordinary temperature from that of a thick syrup to a moderate vis- 'cosity. In order to avoid the difiiculties arising in the treatment of viscous masses, according to the invention an excess of aniline is used, taking advantage of the circumstance that aniline sulphonate is soluble in aniline. In this way two layers are formed viz. an aqueous top layer containing all the sulphuric acid in the form of aniline sulphate and also some free aniline, and a bottom layer consisting of a solution of aniline sulphonate in aniline, which at ordinary temperature is of a thin liquid consistency. It will be obvious that the quantity of water must be sufiicient to keep all the aniline sulphate dissolved at the temperature used in the process, which preferably should be 80-90 C.

These two layers, which separate quite distinctly and after a very short time, may be easily removed from each other, whereupon each of them is treated further separately and in an 1 appropriate manner.

The bottom layer (aniline sulphonate layer) is first neutralized with alkali or ammonia, and then the aniline and water are distilled off, for instance in vacuum. As the distillation pro- 1 ceeds the solution turns; to a viscid consistency and finally a solid, brittle and easily pulverizable mass of sulphonic acid salts is obtained. It is to be noted that in the preparation of ammonium sulphonates, in view of the relative af- 3 the latter layer a large part 65 finitiesof ammonia and aniline, the aniline must be distilled'ofi, either in vacuum or by a steam or the like distillation.

from the salts in any known manner. The ani- There are various Ways, in which the top layer (aniline sulphate) may be treated. In one em-.

bodiment of the process tion this layer is treated lime, whereby calcium sulphate is precipitated according to the invencarbonate or the like. Magnesium sulphate is thereby produced, which dissolves in the water retained by the crystallized aniline sulphate, whilst the greater part of the aniline made free passes into a separate layer and can be returned at once into the process for re-use. small quantity of aniline still remaining in the magnesium sulphate solution can be extracted by means of a steam injection.

The process according to the invention, which is absolutely safe in working, can be applied to all 'sulphonic acids produced from mineral oil, as also to various sulphonic acids produced from other sources, as for instance from residual sulphite lye. From the crude liquors to be purified the sulphonic acids are recovered quantitatively and in a very pure state. Instead of aniline, other organic bases, such that it can readily be distilled off from the alkali sulphonates which are obtained in solution in said base.

Example I phomc are distilled off. The aqueous top layer is cooled down to -30 C., whereupon a crystal mass of aniline sulphate settles It is recommendable tocarry out the distilla with quick or hydrated pulp process is acid and from which the acid Example II A residual sulphite liquor from a sulphite paper 10% by weight of concentrated hydrochloric acid, after which as tained in the liquor in the form of aniline salts in the bottom layer. This layer is separated from the supernatant layer,

Example III a spindle oil fraction which has been with sulphuric acid or From eated and naphthenic acids are left behind.

The products obtained according to this invention are extraordinarily suitable, according to their nature, ifiers or stabilizers in the Further the purified products are highly suitable for the breaking or de-emulsifying of emulsions of an aqueous phase in a non-aqueous phase, such as petroleum emulsions and the like.

I claim:

2. A process according to claim precipitated compounds of 1, in which the the organic base and suI-phonic acids after separation from the remainth an agent capapounds which are cids out of said b sulphonic acids ording to cl an aqueous solution nic acids which solution with cts with the sulacids present in said the resulting layers,

tallize out aniline ining motherntity or aqueous,

s for treating of acid sludge compounds, an or their salts fr 3. The process acc to recover sulpho me said acid slu whereby the aniline phuric acid and sul sludge solution, sep cooling the upper layer and recycling treatment or a fresh qua acid sludge solution.

11. A process accor aim 1 in which ds of the org d are treated with an eparate sulphonic ac remaining aqueous alkali in order to s the organic base.

4. A process a' sufflcient excess of org the precipitated oompoun and sulphonic acids.

to claim 1, in which a is used to dissolve ds of the organic base of salt of the organic base reagent in order to separate the honic acids.

claim 1, in which the of salt of the or terial selected from the group magnesium caronate in order from the sulphonic in which the of the electrolyt treatment of the aqu sulphonic acids.

6. A process accor of the salts of the organi remaining aque and the mother batches of sulp base recycled for further 6. containing the consisting of magne bonate and b to separate the org ding to claim 1, in which part asic es ained in the insolubilized by cools recycled to honic acids to be mm are 13. A process the aqueous liqui of acid sludge.

14. A process acco the aqueous li of acid sludge from which a the free sulphuric aci prelimina y according to claim d treated is an aqu 1, in which dissolve fresh eous'solution rding to claim 1, in which ed is an aqueous solution substantial part of d has been rem rocess according to claim 1, in which an amine is used as the organic base.

8. A process ac aniline is used as 9. A process accor cording to claim 1, in

the organic base.

ding to claim 1, in which an of such volatility that it can from the sulphonic comess according to claim 1, in which the aqueous liquid treated is a residual sulphite liquor. HYMAN LIMBUR readily be di obtained in the presenc of said 

